How to add panel into 3D view port (beside object 3D)
Setting bl_space_type = 'VIEW_3D' will place your panel within the 3dview. You then set bl_region_type = 'TOOLS' to have it show in the tools region while the less intuitive bl_region_type = 'UI' places it in the properties region.

If you want to place a panel in the properties editor, you would set bl_space_type = 'PROPERTIES' and bl_region_type = 'WINDOW', then you set bl_context to match the context you want it shown in - Object, Scene, World, Modifier...

Also remember that you need to register your panel class -

def register():
    bpy.utils.register_class(MyPanel)